Lennox VOSA036S4 User manual

1
©2017 Lennox Industries Inc.
Dallas, Texas, USA
INSTALLATION
INSTRUCTION
VRF SYSTEMS -- Indoor Units
507447-01
03/2017
THIS MANUAL MUST BE LEFT WITH THE OWNER
FOR FUTURE REFERENCE
Shipping and Packing List
General
The VOSA dedicated outdoor air concealed ducted
indoor units are matched with an outdoor heat pump
unit (excluding Mini-VRF) to create a VRF (variable
refrigerant flow) system that uses HFC-410A refrigerant.
Refer to the Product Specification bulletin (EHB) for
the proper use of these indoor units with specific heat
pumps, heat recovery units, mode switching devices,
branch pipes, line sets and controls.
VOSA Outdoor Air Units
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
Check the components for shipping damage. If you find
any damage, immediately contact the last carrier.
Package 1 of 1 contains the following:
1 - Assembled dedicated outdoor air concealed ducted
unit
Refrigerant piping insulation sleeves
2 - VOSA036 and VOSA048
4 - VOSA054 and VOSA072
1 - Flexible condensate connector (VOSA036-048)
1 - Hose clamp (VOSA036-048)
1 - Condensate connection pipe (VOSA054-072)
1 - Roll tape for condensate pipe (VOSA054-072)
1 - Branch pipe kit (VOSA054-096)
Flare Nuts
1 - VOSA036-048
2 - VOSA054-096
2 - Connector for electronic expansion valves and liquid
lines (VOSA054-072)
1 - Resistor
1 - Installation manual
WARNING
Improper installation, adjustment, alteration, ser-
vice or maintenance can cause property damage,
personal injury or loss of life.
Installation and service must be performed by a li-
censed professional HVAC installer, service agency
or the gas supplier.
Failure to follow safety warnings and these instruc-
tions exactly could result in property damage, dan-
gerous operation, serious injury, or death.
Any additions, changes, or conversions required in
order for the appliance to satisfactorily meet the ap-
plication needs must be made by a licensed profes-
sional HVAC installer (or equivalent) using factory-
specified parts.
Do not use this system if any part has been under
water. A flood-damaged appliance is extremely dan-
gerous. Immediately call a licensed professional
HVAC service technician (or equivalent) to inspect
the system and to replace all controls and electrical
parts that have been wet, or to replace the system, if
deemed necessary.
The State of California has determined that this
product may contain or produce a chemical or
chemicals, in very low doses, which may cause
serious illness or death. It may also cause cancer,
birth defects, or reproductive harm.
CAUTION
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves and
protective clothing.
IMPORTANT
The Clean Air Act of 1990 bans the intentional venting
of refrigerant (CFC’s and HCFC’s) as of July 1, 1992.
Approved methods of recovery, recycling or reclaiming
must be followed. Fines and/or incarceration may be
levied for non-compliance.
NOTE - VOSA054 and VOSA072 units have special
wiring and piping considerations, see page 17.

2
Model Number Identification
Safety Requirements
ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD.
Do not touch the unit or the controller if your hands are wet.
DO NOT spray water on the indoor unit for any reason.
Do not replace a fuse with a fuse of a different rating. Do not use a jumper wire to replace a fuse. Do not insert
your hands, tools or any other item into the air intake or air outlet at either the indoor or outdoor unit.
Do not allow children to operate the system.
WARNING
!
V OS A 036 S 4 - 1 P
Brand/Family
V = Variable Refrigerant Flow (VRF)
Major Design Sequence
A = 1st Generation
Cooling Efficiency
S = Standard Efficiency
Refrigerant Type
4 = R-410A
Minor Design Sequence
1 = 1st Revision
2 = 2nd Revision
3 = 3rd Revision
Voltage
P = 208/230V-1 phase-60hz
Nominal Cooling Capacity - Btuh
036 = 36,000 Btuh
048 = 48,000 Btuh
054 = 54,000 Btuh
072 = 72,000 Btuh
System Piping
CAUTION
VRF system piping is customized for each installation.
The LVSS piping report is an engineered design that
must be followed. The piping diagram or diagrams
included within the LVSS report have been prepared
based on the information provided to the Lennox VRF
applications department.
When the indicated lengths change from the figures
stated within the report, it is imperative that prior to the
commencement of the refrigerant pipe work installation,
Lennox VRF applications department are informed of
these proposed changes.
Upon receipt of this new information the Lennox VRF
applications department will confirm any changes that
may be applicable to this installation. If changes are
required, a new piping diagram will be produced and will
supersede all other previously provided documents.
Failure to provide this information regarding changes
to the original design may lead to insufficient capacity,
equipment failure, warranty being made void and the
refusal to commission the system.
Unit Type
OS = Dedicated Outdoor Air Concealed Ducted Indoor Models

3
Unit Dimensions - Inches (mm)
VOSA036S4, VOSA048S4
AIRRETURN
AIRSUPPLY
LIQUID
PIPE
GAS
PIPE
RETURN AIR VIEW
TOP VIEW
SUPPLY AIR VIEW
HOLES FOR SUSPENDING (4)
42-1/4 (1073)
(Duct Opening)
45-1/4 (1149)
13-3/8 (339)
(Duct Opening)
2-1/2
(65)
3-1/4
(83) 1-1/4
(38)
3-1/4
(83)
2 (51)
SUPPLY AIR
DUCT FLANGE
1-3/8
(35)
10 (253)
3/4 (19)
RETURN AIR
DUCT FLANGE
25-1/8
(638)
23-5/8
(600)
3-1/2
(89)
2-3/4
(70)
5-3/8 (137)
5/8 (16)
DRAIN
CONNECTION
(Either Side)
ELECTRICAL
CONTROL
BOX
51-1/4 (1302)
36-5/8 (930)
3-1/4
(83)
5-3/8
(109) 1-1/8 (29)
9-7/8 (251)
(Duct Opening)
3-1/2
(89)
16-1/2
(419)
10-5/8
(270)
2-1/4 (57)

4
LEFT SIDE VIEW RIGHT SIDE VIEW
ELECTRONIC
EXPANSION
VALVE
LIQUID
PIPE
GAS
PIPE
DRAIN
CONNECTION
(Either Side)
AUXILIARY
DRAIN
CONNECTION
(Either Side)
4-7/8 (124) 7-3/8 (187)
1-5/8
(41)
27-1/4
(692)
1-3/8
(35)
9-7/8
(251)
(Supply
Air Duct
Opening)
4-7/8
(124)
7-3/8 (187)
1-5/8 (41) 1/2 (11)
1/2
(11)
13-3/8
(339)
(Return
Air Duct
Opening)
2
(51)
VOSA036S4, VOSA048S4
16-1/2
(419)
ELECTRICAL
CONTROL
BOX

5
Unit Dimensions - Inches (mm)
2-1/4 (57)
AIRRETURN
DRAIN
CONNECTION
AIRSUPPLY
SUPPLY AIR VIEW
TOP VIEW
RETURN AIR VIEW
VOSA054S4, VOSA072S4
44-1/8 (1121)
(Duct Opening)
3
(76)
13-1/2 (343)
(Duct Opening)
2-3/8 (60)
3-7/8 (98)
RETURN AIR
DUCT FLANGE
HOLES FOR
SUSPENDING (4)
ELECTRICAL
CONTROL
BOX
56-3/4 (1141)
SUPPLY AIR
DUCT FLANGE
50-1/4 (1276)
32
(813)
2-5/8 (67)
15 (381)
(Duct Opening)
2 (51)
37 (940)
(Duct Opening)
8 (203)
18-1/2
(470)
RIGHT SIDE VIEW
2-3/4
(70)
1-3/4 (44)
5 (127)
4
(102)
ELECTRONIC
EXPANSION
VALVES
GAS
PIPES (2)
LIQUID
PIPES (2)
LIQUID
PIPES (2)
GAS
PIPES (2)

6
Clearances
Refer to figure 1 for minimum clearance requirements.
20” (508 mm) Minimum Service Clearance
24” (610 mm)
Air
Flow
24” (610 mm)
Minimum
Service
Clearance
TOP VIEW
FRONT VIEW
1” (25 mm) Minimum Clearance
Ceiling
Wall
Wall
1” (25 mm) Minimum Clearance
CeilingSuspended
Minimum
Service
Clearance
Figure 1. Minimum Installation Clearances
NOTE - No part of the suspended ceiling, or other supports not directly associated with the indoor unit installation, can
be fixed to, or touch the indoor unit, in any form. Minimum clearances must be observed at all times.

7
Unit Placement
AVOID
Do not install the unit in the following locations:
• Areas exposed to petrochemicals or petrochemical
products
• Areas exposed to salt or other corrosive materials or
caustic gasses
• Areas exposed to extreme voltage variations (such as
factories
• Tightly enclosed areas that may impede service of the
unit
• Areas exposed to fossil fuels (such as oil or gas in
kitchens)
• Areas exposed to strong electromagnetic forces
• Areas exposed to acids or alkaline detergents (laundry
rooms)
DO:
• Locate the unit so that it is not exposed to direct
sunlight
• Ensure the structural ceiling can support the weight
of the unit.
• Select a location where condensate line will have the
shortest run to a suitable drain per local codes.
• Allow sufficient space around unit for proper operation
and maintenance
• Install unit a minimum of 3 feet away from any antenna,
power cord (line) radio, telephone, security system, or
intercom. Electrical interference and radio frequencies
from any of these sources may affect operation
CAUTION
Do not place items which may be damaged by water
under or around the indoor unit.
The unit should be installed at least 8 feet above the
floor (if possible) to ensure maximum performance
and comfort, when installed in the horizontal
position only.
WARNING
Use the provided and specified components when
installing equipment. Failure to do so may result
in unit falling, water leaking or electrical shocks,
causing personal injury or equipment or property
damage.
Check stability of wall, floor, or ceiling and unit
support. If support is not capable of carrying
weight of the unit, unit may fall causing personal
injury or equipment damage.
Consider the possibility of earthquakes in your
area when installing the equipment. If the unit is
not correctly secured, it may fall, causing personal
injury or equipment damage.
Safely dispose of packing materials, which include
nails, wood and other sharp objects, as well as
plastic wrapping. Children playing with plastic
wrap or bags risk the danger of suffocation.

8
Installation
It is important to locate the unit where it can be accessed
for service in the future. Refer to unit dimensions on Page
3 for exact locations of suspension brackets, return air
and supply air openings.
1. Make sure that the structural ceiling or slab is able
to support the weight of the indoor unit. It may be
necessary to add extra support.
2. Install suspension rods in the structural
ceiling or concrete slab in a suitable location.
If the structural ceiling is constructed of concrete,
install anchors to accept four ⅜” threaded rods to
suspend the indoor unit. If the structural ceiling
includes wooden joists, use angle iron or Unistrut
channel fixed securely in place to accept the ⅜”
threaded rods. NOTE - Threaded rod (requirement
of Lennox warranty program) is the ONLY acceptable
method of suspending the unit; do not use chains or
straps. See figure 2.
3. Slide one nut and one washer onto each threaded rod.
Use electrical tape to keep the washer from failing off.
Position the nuts slightly above the final resting place
of the four suspension brackets. See figure 3.
Figure 2. Suspending Methods
ANGLE IRON
BOLTED IN
PLACE ACROSS
WOODEN JOISTS
WOODEN JOIST
Ǫ´7+5($'(D
ROD ANGLE IRON
ACROSS
WOODEN JOISTS
$1&+25
CONCRETE CEILING
USING ANCHORS
Ǫ´7+5($'(D
ROD
4. Use either a mechanical lifting device or a minimum
of two people to raise the unit and insert the threaded
rods into the suspension brackets on the cassette
base. Slide a washer and then a nut onto each rod
below each suspension bracket. Use the leveling nut
(beneath suspension bracket) to adjust the unit to the
correct height. Remove the electrical tape holding the
upper washers and nuts in place and tighten each
of the four nuts above the brackets down onto the
brackets. This will ensure that the unit remains level.
5. If necessary, install a field-provided isolation grommet
as shown in figure 4 to prevent transmission of
vibration from unit to structural ceiling.
6. If the unit is being installed in an application that includes
a sheet rock (plasterboard) ceiling, it is required that
an access panel be installed in a suitable location.
This will also allow access for future maintenance
(requirement of Lennox warranty program).
Access is required during the commissioning process
to test the condensate disposal system (See figures
10, 11 and 12), to check the electronic expansion
valve and associated flare nuts (See figure 5), and to
check the local disconnect.
7. The unit is factory-configured for the supply air to be
delivered from the front and the return air filter at the
rear of the unit.
INSTALLATION GUIDELINES
• Install a field-provided isolation grommet as shown in
figure 4 to prevent transmission of vibration from unit
to structural ceiling.
• Provide separate support for the weight of the duct
system. Duct system must not be supported by the
indoor unit.
• Use flexible joints (canvas) at the point where the duct
connects to the unit on both ends. Material must meet
all local and national code requirements.
• When unit is being installed in a location where even
the slightest noise would be a problem (meeting room
or other very quiet space), design duct system to
avoid transmission of vibration to the structure to the
extent possible.
LEVELING
NUT
Ǫ” THREADED
ROD
SUSPENSION
BRACKET
FIELD-PROVIDED
ISOLATION GROMMET
WASHER
INDOOR UNIT
LEVELING
NUT
Ǫ” THREADED
ROD
SUSPENSION
BRACKET
SUPPLY AIR
OPENING
FRONT VIEW
When unit is
level, tighten
nut to secure
position of
suspension
bracket on
rod.
Figure 3. Suspension Hardware
Figure 4. Isolation Grommet

9
Refrigerant Piping Connections
Field piping consists of two copper lines connected to the
indoor unit. Table 1 lists the connection sizes at the indoor
unit. The connections are made using the provided brass
flare nuts at the end of the refrigerant piping connections.
Both lines must be individually insulated.
NOTE - Always slide a flare nut onto the field-provided
refrigerant piping before flaring the lines.
1. The seal on the unit refrigerant piping connections
should remain in place until the last possible moment.
This will prevent dust or water from getting into the
refrigerant piping before it is connected.
2. Slowly loosen one of the flare nuts to release the
factory nitrogen charge.
3. Remove the flare nuts and discard the seal from each
of the piping connections.
4. Slide the flare nuts onto the ends of the field-provided
refrigerant piping before using a suitable flaring tool to
flare the end of the copper pipe.
System Size
(Btuh) Liquid Line Vapor Line
36000
48000 3/8” 5/8”
54000
72000 3/8” (2) 5/8” (2)
Table 1. Refrigerant Piping Connections
5. Apply recommended HFC-410A refrigerant lubricant
to the outside of the field-provided flared line sets
(figure 5 -- A).
6. Align the union tube and flared refrigerant lines with
each other, then tighten the flare nuts lightly at first to
obtain a smooth match (figure 5 -- B).
Figure 5. Making Connections at Indoor Unit
(Male to Female Connection)
7. Once snug, continue another half-turn on each nut
which should create a leak-free joint. A torque wrench
may be used to tighten flare nuts using Table 2
recommendations. See figure 6. Do not over-tighten
a flared joint.
A
B
CANT ON THE OUTSIDE OF
THE FLARE
MALE FLARE
CONNECTION
TORQUE WRENCH
TO INDOOR
UNIT
TO OUTDOOR UNIT
BACKUP
WRENCH
Figure 6. Tighten Flare Nut
NOTE - See page 21 for additional piping instructions for
VOSA054 and 072 units.
WARNING
Refrigerant leaks are unlikely; however, if a
refrigerant leak occurs, open a door or windows to
dilute the refrigerant in the room. Turn off the unit
and all other appliances that may cause a spark.
Call a licensed professional HVAC technician (or
equivalent) to repair the leak.
Use only R410A refrigerant to charge this system.
Use of other refrigerant or gas will damage the
equipment.
Do not allow air or other contaminants to enter
system during installation of refrigerant piping.
Contaminants will result in lower system capacity
and abnormally high operating pressures and may
result in system failure or explosion.
Insulate all refrigerant piping.
Refrigerant pipes may be very hot during unit
operation. Do not allow contact between wiring and
bare copper pipes.
After refrigerant piping connections have been
completed, check the system for leaks per
commissioning instructions.
IMPORTANT
The compressor in this unit contains PVE
oil (Polyvinylether). PVE oil is formulated for
hydrofluorocarbon (HFC) refrigerants, such as R-
410a, which this system contains. While it may have
some miscibility properties with mineral-based oil
and POE oil (Polyolester), it is not recommended to
mix PVE oil with any other type of refrigerant oil.
IMPORTANT
Always use two wrenches when tightening flare
nuts to avoid twisting refrigerant piping. DO
NOT over-tighten flare nuts.

10
Outside
Diameter Recommended Torque No torque wrench available
Finger tighten and
use an appropriately
sized wrench to turn an
additional:
Inches U.S.
3/8” 26 ft.-lb. 1/2 turn
5/8” 48 ft.-lb. 1 full turn
Table 2. Flare Nut Torque Recommendations
Figure 7. Insulate Flared Connections
UNIT
BASE
INSULATE ALL FLARED CONNECTIONS
TO PREVENT CONDENSATION
8. Flared connections should always be accessible and
must be insulated to prevent condensation. See figure
7.
Figure 8. VOSA054/072 Refrigerant Connections
Incoming
liquid line
connection
Incoming
liquid line
connection
Incoming
suction line
connection
Incoming
suction line
connection
Connect
these two
pipes
Connect
these two
pipes
Figure 9. VOSA036/048 Refrigerant Connections
9. Locate the pre-formed copper connector pipes
provided in the bag assembly (VOSA054-072 only).
These pipes are used to connect the unit piping to the
electronic expansion valves. Remove the plastic seal
from each end of the pipe. See figure 8.
10. Apply a small amount of recommended HFC-410A
refrigerant lubricant to the outside of the flared ends
of the connector.
11. Immediately align the connector pipe with the identified
piping in figures 8 & 9. Hand-tighten the flare nuts at
first. Then, use two wrenches to continue to tighten
the nuts without twisting the pipes. See figure 6.
Torque requirements are given in table 2. Again, do
not over-tighten the flared joints.
12. After refrigerant piping has been installed and
checked for leaks, apply insulation over the connector
pipes and all flared connections.
Incoming
liquid line
connection
Incoming
suction line
connection

11
Condensate Piping Connections
1. Use the provided hose clamp to secure the
provided flexible condensate drain connector
and insulating sleeve to the drain line stub
on the side of the indoor unit. See figure 10.
NOTE - Take care not to over-tighten the hose clamps
this may damage the drain line stub.
2. Make a water-tight connection between the field-
provided condensate drain line and the flexible
condensate connector (VOSA036-048 5/8” I.D.,
VOSA054-072 1” I.D.).
INSULATION
INDOOR
UNIT
CONDENSATE
LINE STUB HOSE CLAMP
FLEXIBLE DRAIN
CONNECTOR PVC DRAIN
PIPE
CONTROL
BOX
(Bottom of Unit)
PRIMARY
DRAIN
CONNECTION
(Either Side)
AUXILIARY
DRAIN
CONNECTION
(Either Side)
024 shown
Figure 10. Condensate Drain Connection
3. See figure 11 for applications including a single unit
and a single drain. In this case, ensure that the drain
line is properly sloped (no less than 1/4 inch per foot)
and condensate lines are routed to ensure moisture is
drained away from the indoor unit.
Suspension Rods
Drain line
Structural Ceiling
3 ft.
(1 m)
Support
straps
NOTE - Drain line should be sloped 1/4 inch per foot (18 mm per m)
AWAY from unit and should be supported as needed to prevent sagging.
Do not overtighten drain fitting.
Do not operate unit without condensate drain trap.
Clean Out
Do not glue
3”
3”
Anti-siphon vent must extend above the
height of the coil drain pan by 2” (51 mm).
1 ft.
(305 mm) max
Indoor Unit
Figure 11. Sloped Condensate Drain -- Single Unit
Indoor Unit tinUroodnItinUroodnI
Install a trap for each indoor unit.
3”
3”
Clean Out
Do not glue
3”
3”
3”
3”
Suspension
Rods
3 ft.
(1 m)
Support
straps
NOTE - Drain line should be sloped 1/4 inch per foot (18 mm per m)
AWAY from unit and should be supported as needed to prevent sagging.
Do not overtighten drain fitting.
Do not operate unit without condensate drain trap.
Install an anti-siphon vent for each trap - must extend above
the height of the coil drain pan by 2” (51 mm).
1 ft.
(305 mm) max
Clean Out
Do not glue Clean Out
Do not glue
Vent Vent
Figure 12. Using a Main Drain to Serve Multiple Indoor Units with Gravity Drains
CAUTION
Make sure that drain piping is properly routed and
insulated in order to prevent both leaks and condensation.
Follow these instructions exactly to ensure proper
drainage and unit operation.
IMPORTANT
You must confirm operation of every drain and pump in
the system as part of the commissioning procedure.
IMPORTANT
Drain should have a slope of at least 1/4 inch per foot
and should be approved corrosion-resistant pipe.
4. See figure 12 for applications including multiple units
and a single drain. In this case, ensure that the drain
line is properly sloped (no less than 1/4 inch per foot)
and condensate lines are routed to ensure moisture
is drained away from the indoor unit.
5. In all cases, drain should be as short as possible and
should not have any droops or kinks that would restrict
condensate flow and shall be constructed using an
approved pipe. All drains should contain traps. There
must be a 2-inch space between the end of the
condensate drain and the final termination point
(ground, open drain, etc.) to ensure that the line
will drain freely.
6. After system installation is complete, the
condensate drain line must be checked for leaks
and if a condensate pump has been fitted, it must
be checked to ensure proper operation. This
check is part of the commissioning procedure.

12
Wiring Connections In the U.S.A., wiring must conform with current local codes
and the current National Electric Code (NEC). In Canada,
wiring must conform with current local codes and the
current Canadian Electrical Code (CEC).
Refer to unit nameplate for minimum circuit ampacity and
maximum overcurrent protection size.
NOTE - Three-conductor stranded shielded cable must be
used for the communication wiring. This is necessary to
ensure proper system communication and operation.
• A circuit breaker capable of shutting down the power
supply to the entire system must be installed.
• A single switch can be used to supply power to units
on the same system. However, branch switches and
circuit breakers must be selected carefully.
• Fit the power supply wiring of each unit with a switch
and fuse as shown in the wiring diagram.
• Install a wiring interrupter or ground-fault circuit
interrupter for the power wiring.
• Make sure the ground resistance is no greater than
100Ω. This value can be as high as 500Ωwhen using
a grounding fault circuit interrupter since the protective
ground resistance can be applied.
1. Remove the screws that secure the control box cover.
Remove the cover and place it to the side where it will
not be damaged.
2. Locate the terminal strip in the control box. Connect
the power wiring (sized per NEC/CEC and local codes)
and communications cable (three-core, shielded
cable). Refer to unit nameplate for rated voltage.
3. If the indoor unit is the final unit in a group that is wired
in series, install the provided resistor across terminals
P and Q.
4. The infra-red receiver / display panel is factory installed
and can be repositioned, if necessary. Use optional
extension cable kit V0CTRL93P-1 (cat # 14R84).
NOTE - See page 27 for wiring and piping instructions for
VOSA054 and 072 units.
WARNING
Isolate the power supply before accessing unit electrical
terminals.
Install unit so that unit disconnect is accessible.
Follow all local and national codes, as well as this
installation instruction, during installation. Do NOT
overload electrical circuit, as this may lead to failure and
possible fire.
Use specified wiring and cable to make electrical
connections. Clamp cables securely and make sure that
connections are tight to avoid strain on wiring. Insecure
wiring connections may result in equipment failure and
risk of fire.
Wiring must be installed so that all cover plates can be
securely closed.
CAUTION
This unit must be properly grounded and protected by a
circuit breaker. The ground wire for the unit must not be
connected to a gas or water pipe, a lightning conductor
or a telephone ground wire.
Do not connect power wires to the outdoor unit until
all other wiring and piping connections have been
completed.
Install all wiring at least 3 feet away from televisions,
radios or other electronic devices in order to avoid the
possibility of interference with the unit operation.
Do not install the unit near a lighting appliance that
includes a ballast. The ballast may affect remote control
operation.
CAUTION
A disconnection device having an air gap contact
separation in all active conductors should be
incorporated in the fixed wiring according to the National
Wiring Regulation.

13
PQE CommunicaƟon wiring
Electrical disconnect switch
Legend
Power DistribuƟon Box
L1/L2
L1/L2
L1/L2
L1/L2
L1/L2
L1/L2
PQE
PQE
PQE
PQE
L1/L2
L1/L2
L1/L2
L1/L2
PQE
PQE
PQE
PQE
PQE
L1/L2
L1/L2
L1/L2
PQE PQE
L1/L2
L1/L2
L1/L2
PQE
PQE
PQE PQE
L1/L2
L1/L2
L1/L2 Single-Phase power wiring
Figure 13. Typical Power Wiring Diagram (VRF Heat Pump System Shown)
Tightening torque for the terminal screws
• Use the correct screwdriver for fighting the terminal
screws. If the screwdriver blade is too small, the head
of the screw might be damaged, and the screw will not
be properly tightened.
• If the terminal screws are over tightened, screws
might be damaged.
• Refer to the table below for the tightening torque of
the terminal screws.
Table 3. Terminal Screw Tightening Torque
Tightening torque (lb-ft)
Terminal base of
remote controller/Signal
transmission wire (X2M)
0.58-0.72
Terminal base of power
supply (X1M)
0.87-1.06
Grounding terminal (M4) 1.06-1.43
• After wiring, confirm all connections are correct; Then
turn on power supply to the unit.
IMPORTANT
DO NOT adjust DIP switch settings. Settings may only
be adjusted by a trained technician as part of the com-
missioning procedures.

14
Figure 14. Typical Communication Wiring Diagram (VRF Heat Pump System Shown)
(PQE)
(PQE) Ground cable shield
DO NOT connect to E
Outdoor unit
(main unit) Outdoor unit (sub1 unit) Outdoor unit (sub2 unit)
(H1 H2 E) (H1 H2 E) (H1 H2 E)
Install a terminating resistor at the last indoor unit terminals P and Q of the daisy
chain.
P Q
All shields of shielded cable connect to GROUND terminal, not to terminal E.
18 GA., stranded, 3-conductor, shielded control wire (polarity sensitive).
Typical Wiring Diagram, NEC/CEC and Local Codes apply.

15
Figure 15. VOSA036S4-1 and VOSA048S4-1 Typical Wiring Diagram
Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring.
&1
&1
)0
&
75
;7
7
:+,7(
7%
7
%/$&.
<(//2:*5((1
6: 6: 6: 6:
(1&
- 21
21
21
21
&1 &1
&1
3
&1
((9
&1
3
&1 &1δ:+,7(ε&1δ<(//2:ε
;6
;3
;6
;3
:+,7(*5$<
<*
:+,7(
0$,1 &21752/ %2$5'
5('
%/8(
:,5('
&21752//(5
&1
&1
ALARM
5('
&1
BLACK
TA

5< 5< 5<
&1
;6
,1'225 32:(5
/ L2
&1
&1
&1
;7
P Q (E)XY
(E)
32:(5B6
;6 ;3
:((./< 7,0(5
:,5(' &21752//(5
',63/$< %2$5'
127(φ
&20321(17 ,1 '$6+
/,1( ,6 237,21$/
25 ),(/' :,5,1*
&21752/ ,17(5)$&(
02'8/(
*5281'
*5281'
WATER
LEVEL SWITCH
PUMP MOTOR
EEV
T2B
T2
TR
FM
XS1-7
XP1-7
XT1-2
PUMP
CS
C
KEY
COMPONENT
INDOOR FAN
ELECTRONIC
EXPANSION VALVE
COIL TEMP.
FAN CAPACITOR
TRANSFORMER
TERMINAL BLOCK
EVAP OUTLET TEMP
IN COOLING MODE
PLUG
JACK
GM
SWING MOTOR
T0
INLETAIR TEMP.
TA
OUTLETAIR TEMP.
   
Timer and Run LEDs
flashing simultaneously,
or "FE" displayed
z
No address given on
initial unit start-up
Defrost LED flashing,
or "E0" displayed
zMode conflict
Timer LED flashing
or"E1" displayed
zCommunication error
between indoor and
outdoor unit
RunLED flashing or 2"
displayed "E
zWater level alarm
zTemp sensor (T1) error
zTemp sensor T2 error˄˅
zEeprom error
Defrost LED flashing
slowly or "E7" displayed
Alarm LED flashing
slowly or "Ed" displayed
Alarm LED flashing or
E" displayed"E
zOutdooruniterror
zTemp sensor T2B error˄˅
Run LEDflashingor 3"
displayed "E
Run LED flashing or "E4"
displayed
&211(&7 72
287'225 81,7
&211(&7 72
:,5(' &21752//(5
127(  5()(5 72 0$18$/ )25
&20081,&$7,21 :,5,1*
 3/($6( 86( 7+(
&21'8&725
6+,(/'(' &$%/(

16
Figure 16. VOSA054S4-1 and VOSA072S4-1 Typical Wiring Diagram
Typical wiring diagram. Refer to wiring diagram on the unit for actual wiring.
Timer andRun LEDs
flashing simultaneously,
or "FE" displayed
z
No address given on
initial unit start-up
Defrost LED flashing,
or"E0"displayed
zMode conflict
Timer LED flashing
or"E1" displayed
zCommunication error
between indoor and
outdoor unit
Run LEDflashing or 2"
displayed "E
zWater level alarm
zTemp sensor (T1) error
zTemp sensor T2 error˄˅
zEeprom error
DefrostLED flashing
slowly or "E7" displayed
Alarm LED flashing
slowlyor"Ed"displayed
AlarmLEDflashingor
E" displayed"E
zOutdoor unit error
zTemp sensor T2B error˄˅
Run LEDflashing or 3"
displayed "E
Run LED flashing or "E4"
displayed
0(',80+,*+
&20 &20 &20
5/ 5/ 5/
72 ,1'225 32:(5
;7
&1
0$,1 &21752/ %2$5'%

75%
7%
:+,7(
7%%
7%
%/$&.
&1 &1  &1
&1
&1 &1
((9
&1
&1
&1
&1

75$
7$ 7%$7$
&1 &1 &1
&1 &1
&1 &1
((9
&1
&1  
&1
;6
;3
&1
5<5<5<
&1
0$,1 &21752/ %2$5'$
% 6<67(0 $ 6<67(0
5('
5('
5('
5('
<*
:+,7(
BLACK
:+,7(
',63/ $< %2$5'
&2 1 752/ ,17(5)$&( 02'8/(
TO CCM
COMM. BUS
XY PQ
E
XY PQ
E
;7
;7
*
7 
290-0G2
RL1-3
CAP1(CAP2)
KEY
T2B(A),T2B(B)
T2(A),T2(B)
TR(A),TR(B)
FM1(FM2)
XT1-3
XS0-9
XP0-9
T0(A),T0(B)
EEV
COMPONENT
INDOOR FAN
ELECTRONIC
EXPANSION VALVE
INLETAIR TEMP.
COIL TEMP.
RELAY
FAN CAPACITOR
TRANSFORMER
TERMINAL BLOCK
NOISE FILTER
BLUE
BLACK
TA(A)
TO CCM
COMM. BUS
&1
BLACK
TA (B)
TA(A),TA(B)
EVAP OUTLET TEMP
:, 5 (' &21752//(5
/2:
&1
/ L2
6: 6: 6: 6:
(1&
- 21
21
21
21
32 :(5 B6
6: 6: 6: 6:
(1&
- 21
21
21
21
32:(5B6
&1
IN COOLING MODE
PLUG
JACK
OUTLETAIR TEMP.
GROUND
<* <*<*
127(φ
&20321(17 ,1 '$6+
/,1( ,6 237,21$/
25 ),(/' :,5,1*
&211(&7 72
287'225 81,7
&211(&7 72
:,5(' &21752//(5
127(  5()(5 72 0$18$/ )25
&20081,&$7,21 :,5,1*
 3/($6( 86( 7+(
&21'8&725
6+,(/'(' &$%/(
&211(&7 72
287'225 81,7
&211(&7 72
:,5(' &21752//(5
127(  5()(5 72 0$18$/ )25
&20081,&$7,21 :,5,1*
 3/($6( 86( 7+(
&21'8&725
6+,(/'(' &$%/(

17
VOSA054 and 072 Piping and Wiring Connections
VOSA054 and 072 units have two control boards in the
control box and have two gas pipes, two liquid pipes, two
branch pipes and two electronic expansion valves (EXV).
Control box
EXV B
EXV A
Condensate pipe
Refrigerant piping
(two sets)
The additional boards and piping connections require
special considerations when connecting the piping and
communication wiring.
Figure 28. VOSA054 and 072 Unit Identification
LED Display
Inside of Control Box
Control board A
Control board B
Terminal block

18
Figure 29. VOSA054 and 072 Main Control Boards
Figure 30. VOSA054 and 072 Terminal Block
Terminal Block A
PQE Terminal Block B
PQE
Control Board B - Top
Control Board A - Bottom
Communication (PQE) Wiring
NOTE - Control board A is the bottom control board and
Control board B is the top control board in the electronic
control box.

19
Connect the incoming PQE wiring to the terminal block for
Control board A.
If this is the last indoor unit in the system, no additional
PQE wiring is needed.
Add a resistor between P and Q on Control board B.
Main Control Board
A
Main Control Board
B
X Y E P Q
Terminal set A Terminal set B
IDU Control Box
Wiring in
X Y E P Q
Main Control Board
A
Main Control Board
B
X Y E P Q
Terminal set A Terminal set B
IDU Control Box
X Y E P Q
Wiring in Wiring out
If there are additional indoor units, the outgoing wiring is
connected to the terminal block for Control board B.
IDU Control Box
V0STAT51
Controller
Plug in
Main Control Board
B
X Y E P Q
Terminal set A Terminal set B
X Y E P Q
Main Control Board
A
CN10
Wiring out
IDU Control Box
V0STAT51
Controller
Plug in
Main Control Board
B
X Y E P Q
Terminal set A Terminal set B
X Y E P Q
Main Control Board
A
CN10
Connecting V0STAT51
Connect the V0STAT51 cable to the cable attached to
Control board A.
To control more than one VHIA072 or 096 unit from the
same controller,
1. Connect the V0STAT51-1P cable to Control board A.
2. Connect Control board B XYE to the next indoor unit
to be controlled by the controller
Figure 31. VOSA054 and 072 Connect Communication
Wires to Single Indoor Unit
Figure 32. VOSA054 and 072 Connect Communication
Wires to Additional Indoor Units
Figure 34. VOSA054 and 072 Connect to Additional
Indoor Units
Figure 33. VOSA054 and 072 Connect to Single Indoor
Unit

20
Liquid pipe Gas pipe
VOSA054/072
Refrigerant Piping
• Use the provided branch pipe kit to connect both sets
of refrigerant line connections.
• Locate branch pipes no more than 32 feet from indoor
unit.
Figure 35. Piping for VOSA054 and 072
• Piping between branch pipe and indoor unit: liquid line
= 3/8” and gas line = 5/8“.
• Consult LVSS piping report diagram for all other piping
sizes.
3/8”
5/8”
32’ maximum distance
between branch pipes and indoor unit
See piping report
for pipe sizes
Liquid branch pipe
(Provided with VOSA unit)
Gas branch pipe
(Provided with VOSA unit)
Figure 37. VOSA054 and 072 Refrigerant Connections
Incoming
liquid line
connection
Incoming
liquid line
connection
Incoming
suction line
connection
Incoming
suction line
connection
Connect
these two
pipes
Connect
these two
pipes